The present invention relates generally to shake or vibration activated mechanisms for operating valves to effect valve closing, and more particularly to such mechanisms which utilize spring means between a valve body and a valve disk or cock, and trigger arm means pivotally mounted on a valve body, with catch means on the trigger arm to retain the valve cock in open position and to disengage from the valve cock to allow the valve cock to rotate to closed position.
There is a great need to provide suitable automatic means, particularly in emergencies, for closing off the valves used to control the flow of gas and water at the main lines outside buildings.
Existing valves are generally operated manually and the valve cock or stem is arranged to be rotated by hand from one position to another or by use of a wrench. In most applications, when a flow valve is used as the main control valve, the valve cock or stem is of the type requiring a wrench to operate. This type of valve, however, has been found to be unsatisfactory during an earthquake. For such an emergency, it is usually recommended that one keep a wrench handy just for the main gas-inlet valve. However, even with a wrench nearby, these valves are not shut off until after an earthquake occurs. Thus, there is a need for a flow-control valve that is activated at the outset of an earthquake by means of the fast and simple operation described herein.
Accordingly, it is an important object of the present invention to provide a vibration-activated, fluid-flow valve that is readily locked in an open mode for continuous flow of fluid, but further includes a vibration-activated, trigger arm which disengages from the valve disk arm, allowing the valve disk arm to be rotated to a closed mode by means of a spring. Thus, the downstream flow line, if ruptured, will not be able to discharge fluid, particularly inside a building.
Another object of the invention is to provide a fluid flow valve of this character that includes a spring interconnected between the valve disk and the valve body, and a trigger arm having a latch tongue at one end and a weight at the opposite end thereof.
A further object of the present invention is to provide a trigger mechanism, whereby the varying amounts of weight at the end of the trigger arm will cause a corresponding varying amount of sensitivity in the trigger arm with respect to its releasing action.
A further object of the invention is to provide a shake or vibration activated valve mechanism for operating a valve which is responsive to either vertical or horizontal shaking or vibration to release a valve disk to rotate to closed position under spring urging.
A still further object of the present invention is to provide a vibration activated valve of this character that is simple and inexpensive to manufacture, it being formed with relatively few operating parts.
It is still another object of the invention to provide a device of this character that is easy to service and maintain.